Aegis uses the LEGO Mindstorms
Vision Command system to track movement
or color and fire Cyberslam missiles. I designed this as an anti-squirrel device to
track and deter the little brutes who were digging up the roots of the plants in
my wife's window boxes. However, after a discussion in the LEGO Mindstorms
forums
about pets chewing through computer cables [ 'ARCHIVE > MISCELLANEOUS > Beware the Killer Rabbit' ], it occurred to me that a squirrel might
well chew through the USB cables and trash the LEGO Cam. In the end I
have just had it kicking around the office to keep co-workers away from my office supplies

Aegis sits on two 6AA battery boxes. The battery boxes do not act as a power source --
they are just heavy (because of the batteries in them) and wide, and so make a stable base.

FIRING

Firing works by rotating the missile magazine around the central axle,
bringing each missile launcher's firing pin into contact with a spring-loaded beam
(on top of the missile assembly, just below the camera). The beam tips the firing pin
of the CyberSlam Missile launcher to release the missile; as the magazine continues to
revolve the beam is pushed back out of the way and then springs back into place ready
to fire the next shot.

MECHANICS

There are three motors: two control the rotation and elevation of the missile launcher,
linked via chain drives to worm screws which turn the large Technic turntables;
the third motor spins the missile launcher to fire the missiles one after another.

OPERATION

The Aegis can operate on single shot (15 second pause between shots) or full auto
(it will empty the magazine in less than a second). The launcher, with the VC
camera mounted above it, can rotate from +90 to -80° vertically (taking 0° to be
the horizon), and from +135 to -135° in the horizontal plane (click
here for an animated GIF). A rotation sensor
tracks the position of each of the motors, and the RCX has a custom NQC program
loaded to interpret the commands from the Vision Command software.